La Niña and Snow

For anyone that enjoys snowstorms (I know that I’m not alone…but it could be close!), this winter could be your season.  This winter has the potential to be active because of a weather condition known as La Niña.  In short, La Niña is an unusual cooling of surface waters across the central and eastern equatorial Pacific Ocean.  The area of the Pacific Ocean that is monitored is called Niño 3.4 which is represented below in black.  The Climate Prediction Center declares La Niña when the three-month average of sea-surface temperatures in Niño 3.4 exceeds the long-term mean by 0.5° Celsius.  I know being 0.5°C from average doesn’t seem like a big deal, but it’s enough to shift global weather patterns.  

This image is courtesy of the Climate Prediction Center

Below is the typical La Niña wintertime pattern.  It shows the polar jet stream tracking into the Ohio Valley, and the subtropical (Pacific) jet stream converging with the polar jet in the west.  This path can act as a storm track and if it happens to set up this way, then southeast Michigan could be in position for many snowstorms moving into our region.  Interestingly, our last snow storm took a very similar path dropping out of Canada into the Central Plains and tracking through the Ohio Valley.

 This image is courtesy of the Climate Prediction Center

 

So what are the chances this happens?  I would say that we have a good chance.  Forecast models are predicting a moderate to strong La Niña through the winter season.  More proof can be seen below on the three-month precipitation probability.  What this map tells us is that our area has a 40%-50% probability of experiencing above average precipitation during January, February, and March.  It isn’t set in stone that we’ll have a wet winter, but the odds do appear to be in our favor.

 This image is courtesy of the Climate Prediction Center